Chronic toxicity and oncogenicity bioassay in rats with the chloro-s-triazine herbicide cyanazine.
J Toxicol Environ Health A
; 60(8): 567-86, 2000 Aug 25.
Article
em En
| MEDLINE
| ID: mdl-10983523
ABSTRACT
Cyanazine is a member of the chloro-s-triazine class of herbicides. Other triazine herbicides have been shown to induce mammary-gland tumors in rats, although the response is unique to the Sprague-Dawley strain. Cyanazine is nongenotoxic. The present study was conducted to evaluate the chronic toxicity and oncogenic potential of cyanazine. Groups of 62 male and female rats were fed diets containing cyanazine at concentrations of 1, 5, 25, or 50 ppm for up to 2 yr. Mean body weight and body weight gain of male and female rats of the 25- and 50-ppm groups were significantly reduced over the course of the study. Food consumption and food efficiency were also reduced in these groups. Survival was not adversely affected in the treatment groups compared to controls. A significant increase in the incidence of masses of the inguinal region was noted among female rats of the 50-ppm group. These masses were correlated with a significant increase in the incidence of female rats with mammary-gland adenocarcinomas and carcinosarcomas. The incidence of rats with malignant mammary-gland tumors was elevated in the 5-, 25-, and 50-ppm groups, although the incidence within the 5-ppm group was within historical controls. There were no other toxicologically significant observations with respect to ophthalmological, clinical laboratory, or pathological evaluations. Under the conditions of this study, the no-observed-adverse-effect level was 5 ppm. Research into the mechanism of action suggests these mammary tumors are mediated through a prolactin mechanism that is thought to be of low relevance to humans.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Triazinas
/
Neoplasias Mamárias Animais
/
Herbicidas
Limite:
Animals
Idioma:
En
Revista:
J Toxicol Environ Health A
Assunto da revista:
SAUDE AMBIENTAL
/
TOXICOLOGIA
Ano de publicação:
2000
Tipo de documento:
Article
País de afiliação:
Estados Unidos